public void TestConstructors()
            {
                
                try
                {
                    DicomAttributeAT attrib = new DicomAttributeAT(DicomTagDictionary.GetDicomTag(DicomTags.AccessionNumber));
                    Assert.Fail("Above statment should throw exception: invalid tag");
                }
                catch (DicomException)
                {
                    
                }

                CreateAttribute();
                
            }
            public DicomAttributeAT CreateAttribute()
            {
                DicomAttributeAT attr = new DicomAttributeAT(DicomTagDictionary.GetDicomTag(DicomTags.FrameIncrementPointer));
                Assert.AreEqual(0, attr.Count);
                Assert.AreEqual(0, attr.StreamLength);

                return attr;
            }